Author: Roman Lebedev Date: 2021-01-06T01:52:37+03:00 New Revision: d15d81ce15e086208f30d99ce2257a75401dc12c
URL: https://github.com/llvm/llvm-project/commit/d15d81ce15e086208f30d99ce2257a75401dc12c DIFF: https://github.com/llvm/llvm-project/commit/d15d81ce15e086208f30d99ce2257a75401dc12c.diff LOG: [SimplifyCFG] FoldValueComparisonIntoPredecessors(): deal with each predecessor only once If the predecessor is a switch, and BB is not the default destination, multiple cases could have the same destination. and it doesn't make sense to re-process the predecessor, because we won't make any changes, once is enough. I'm not sure this can be really tested, other than via the assertion being added here, which fires without the fix. Added: Modified: llvm/lib/Transforms/Utils/SimplifyCFG.cpp Removed: ################################################################################ diff --git a/llvm/lib/Transforms/Utils/SimplifyCFG.cpp b/llvm/lib/Transforms/Utils/SimplifyCFG.cpp index 08005c198298..6d5a68214e7c 100644 --- a/llvm/lib/Transforms/Utils/SimplifyCFG.cpp +++ b/llvm/lib/Transforms/Utils/SimplifyCFG.cpp @@ -1099,7 +1099,7 @@ bool SimplifyCFGOpt::FoldValueComparisonIntoPredecessors(Instruction *TI, ++NumFoldValueComparisonIntoPredecessors; }); - SmallVector<BasicBlock *, 16> Preds(predecessors(BB)); + SmallSetVector<BasicBlock *, 16> Preds(pred_begin(BB), pred_end(BB)); while (!Preds.empty()) { BasicBlock *Pred = Preds.pop_back_val(); @@ -1260,6 +1260,7 @@ bool SimplifyCFGOpt::FoldValueComparisonIntoPredecessors(Instruction *TI, // Okay, at this point, we know which new successor Pred will get. Make // sure we update the number of entries in the PHI nodes for these // successors. + assert(!NewSuccessors.empty() && "Should be adding some new successors."); for (const std::pair<BasicBlock *, int /*Num*/> &NewSuccessor : NewSuccessors) { for (auto I : seq(0, NewSuccessor.second)) { _______________________________________________ llvm-branch-commits mailing list llvm-branch-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-branch-commits
